Malnutrition in the Elderly

When one thinks of an elderly person, the words ‘frail’, ‘thin’, or ‘weak’ likely come to mind. It is true that as one ages, they lose weight. However, it may surprise you that 21.1% to 56.7% of the elderly could be facing malnutrition or be at risk of malnutrition (depending on the subgroup of people). Why is malnutrition so prevalent in the elderly, particularly terminally ill patients? 

When someone is malnourished, they possess deficiencies or imbalances in their intake of energy and/or nutrients. The elderly are particularly prone to not receiving enough nutrients due to four main reasons: reduced intake, impaired absorption, increased requirements, and increased losses.

Reduced intake of food in seniors can be caused by a lack of appetite. Aging hampers our sense of taste, and our favourite dishes just do not taste the same anymore, which can be disappointing. Seniors with dental problems are especially affected due to the inability to chew hard and possibly nutritious foods, with softer alternatives not providing as much nutrition, and they simply may not have the appetite to eat because of the pain or blandness. Additionally, depending on their lifestyle and socioeconomic status, seniors may also have monotonous diets, such that they receive enough calories but not enough vitamins and nutrients. 

As we age, our gastrointestinal system deteriorates, too. Cells responsible for producing hydrochloric acid and digestive enzymes in the stomach and pancreas, respectively, decrease in number and function. Low stomach acid production reduces the absorption of Vitamin B12, iron, calcium, and magnesium. Pancreatic enzymes are crucial for fat and fat-soluble vitamins (A, D, E, K). Our gut microbiome composition is also altered by factors such as a weaker immune system and antibiotic usage, and since the microbes in our gut help in the production of certain B vitamins and conversion to the active form of Vitamin K, there is insufficient absorption of these compounds, too.

Interestingly, severe chronic inflammation and wound healing increase the demand for certain vitamins and proteins, and if not met, lead to malnutrition. Minerals like iron can be lost from chronic blood loss, and potassium/magnesium/calcium can be lost from frequent urination. The usage of medicines can cause nutritional issues as well. They can increase the metabolism of certain minerals, leading to a greater requirement of said minerals, or prevent other minerals from being absorbed as side effects. 

We must also understand that there are many factors as to why we lose weight as we age, and not all of them are due to malnutrition. Physiological changes such as sarcopenia (loss of muscle mass), and hormonal changes such as declines in testosterone, estrogen, or growth hormone can also contribute to weight loss. These are similar to symptoms of malnutrition, but they can also be independently caused. 

It is unfortunate to note that there are many positive feedback loops present that can be hard to tackle. The least we can do is take care of the seniors in our lives, the elderly of our family, and ensure they are eating well. Ensure they have a balanced diet, eat protein-rich and energy-dense foods, and take prescribed supplements if needed. Eating along with others could also help with improving appetite and other food intake issues. Lastly, it is necessary to keep an eye on their well-being and notice if there are signs of wasting or other symptoms. Since each nutrient deficiency has differing symptoms, it is best to have the senior checked out by a doctor.

Written By Chandrahas Anand

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Citations:

1. Salari, N., Darvishi, N., Bartina, Y., Keshavarzi, F., Hosseinian-Far, M., & Mohammadi, M. (2025). Global prevalence of malnutrition in older adults: A comprehensive systematic review and meta-analysis. Public health in practice (Oxford, England), 9, 100583. https://doi.org/10.1016/j.puhip.2025.100583

2. Alibhai, S. M., Greenwood, C., & Payette, H. (2005). An approach to the management of unintentional weight loss in elderly people. CMAJ : Canadian Medical Association journal = journal de l'Association medicale canadienne, 172(6), 773–780. https://doi.org/10.1503/cmaj.1031527

3. Norman, K., Haß, U., & Pirlich, M. (2021). Malnutrition in Older Adults—Recent Advances and Remaining Challenges. Nutrients, 13(8), 2764. https://doi.org/10.3390/nu13082764